Objectives of this project were: (1) to uncover problems a public library might encounter in reclassifying its collection from the Dewey Decimal Classification to the Library of Congress Classification, (2) to apply data processing to the tasks, (3) to establish procedures for reclassification, and (4) to provide a cost estimate for the conversion and processing of a large collection of books. A pilot test involving the reclassification of 1,000 titles in the Providence Public Library was conducted, using the MARC I format in encoding all data. The procedures followed were sample preparation, copy preparation, computer run, book processing for the central library and branches, and card filing for central and branches. It was concluded that the use of mechanized procedures for reclassification seems to be advantageous as far as personnel and time factors are concerned; however, more research is needed on the cost factor. It seems most feasible for the libraries within a region to establish a cooperative reclassification project, with the tapes also forming the basis of a data bank for bibliographies and union lists. Appendixes include: charts of inclusive titles reclassified, sample worksheets, a portion of the study guide for tagging, programming specifications, a sample of card sets and label output, and time and statistics sheets. (JB)